Topic
K-distribution
About: K-distribution is a research topic. Over the lifetime, 1281 publications have been published within this topic receiving 51774 citations.
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TL;DR: In this article, the probability density function (pdf) of optical signal intensity in an optical communication channel impaired by motion-induced beam jitter and turbulence is derived and the conditions for which these approximations seem to be valid are also discussed.
Abstract: Expressions for the probability density function (pdf) of optical signal intensity in an optical communication channel impaired by motion-induced beam jitter and turbulence are derived. It is assumed that the optical beam possesses a Gaussian profile, generated by a pulsed laser, and that the beam scintillation is governed by either log-normal distribution for weak turbulence or K distribution for moderate to strong turbulence in the saturation region. For extreme propagation distances or very strong turbulence, a negative exponential pdf is used to model turbulence. For the aforementioned beam scintillation statistics, approximate pdf's for the signal intensity are also obtained and the conditions for which these approximations seem to be valid are also discussed.
74 citations
TL;DR: In this article, the first-probability distribution and conditional probability distributions of the speech wave instantaneous amplitude were measured for speech waves recorded in an anechoic chamber and for voices recorded in a live studio.
Abstract: Measurements were made of the first‐probability distribution and of various conditional probability distributions of the speech wave instantaneous amplitude. Results obtained for several speakers indicate that the first‐probability distribution varies exponentially with large values of amplitude and that increases in the conditional probabilities are noted for delay times of the order of magnitude of the pitch period.Measurements were also made of the first‐probability distribution of the duration of the speech‐wave zero‐crossing periods, and of the auto‐correlation function of clipped speech.These measurements were of the stationary, or “long‐time,” speech‐wave probability distributions. Most of the results are for speech waves recorded in an anechoic chamber. Some results are included for voices recorded in a live studio.
74 citations
TL;DR: In this paper, a general method for obtaining more flexible new distributions by compounding the extended Weibull and power series distributions was introduced, and the compounding procedure follows the same set-up carried out by Adamidis and Loukas (1998) and defines 68 new submodels.
73 citations
TL;DR: In this paper, an unconditional time-to-failure distribution is derived by assuming that a parameter of a classical failure distribution (viz., exponential and Weibull) is a random variable with a known distribution.
Abstract: Most of the familiar time-to-failure distributions used today are derived from hazard functions whose parameters are assumed constant. An unconditional time-to-failure distribution is derived here by assuming that a parameter of a classical failure distribution (viz., exponential and Weibull) is a random variable with a known distribution. With the use of the derived compound distributions and Bayesian techniques, it is possible to join the test data with prior information to arrive at a combined, and possibly superior, estimate of reliability. The prior distributions considered here are the two-point, the uniform, and the gamma. Conceptually, such a scheme may be a more realistic model for describing failure patterns under specific conditions.
72 citations
TL;DR: In this paper, it was shown that the procedure introduced by Chow and Liu for estimating tree-dependent probability distributions is consistent with the procedure described in this paper. But it is not shown that this is the case for tree-independent probability distributions.
Abstract: We demonstrate in this correspondence that the procedure introduced by Chow and Liu for estimating tree-dependent probability distributions is consistent.
71 citations